a1=1 an*an+1=4^n 求a2n a2n-1 an sn
已知数列{an}满足Sn=(1/4)an+1,求lim(a1+a3+a5+...+a2n-1)的值
已知数列[an]满足Sn=0.25an+1,求a1+a3+a5+……+a2n-1的极限
在以d为公差的等差数列an中,设S1=a1+a2.+an,S2=an+1+an+2+a2n,S3=a2n+1+a2n+a
已知数列an中,a1=1,a2n=n-an,a2n+1=an+1则a1+a2+a3…+a100=
等差数列{an}中,a1=1,a2n=2an+1(n∈N+),Sn是数列{an}的前n项和,求an,Sn,(2)设数列{
设等差数列{An}的前n项和为Sn,S4=4S2,A2n=2An+1 ,(1)求数列{an}的通
设数列an满足a1=4,an=(1/3)(an-1 +2),求lim(a2+a4+...+a2n -3n)
已知等差数列an的首项a1为a,设数列的前n项和为Sn,且对任意正整数n都有a2n/an=4n-1/2n-1,求数列的通
证明等差数列等差数列{an}中,证明[a1+a2+a3……+a2n-1]/(2n-1)=an注:分子上a2n-1中2n-
已知数列an,a1=1,a2n=an,a4n-1=0,a..
已知等差数列{an},若a2+a4+……a2n=a3a6,a1+a3+……=a2n-1=a3a5
已知数列An为等比数列,公比q=-1/3,lim(a1+a3+.a2n-1/a2+a4+.+a2n)的值